Fusible bonds like steam-a-seam are fast and easy, but MUST be sewn down if the item s going to be put through washing machines on a regular basis. Unless I am satin stitching every bit of exposed edge, I also use Fray-check to prevent unravelling.
There are other methods using everything from glu sticks to dryer sheets. Try a couple different ways and you'll find the ones that are easy for you.